This invention relates to the production of images for stereoscopic viewing of sources which emit annihilation radiation.
In the prior art, no satisfactory method or apparatus has been developed to allow accurate stereoscopic viewing of sources emitting radiation. In the field of medicine, there is a need for the ability of physicians to study selected organs or parts of the human body accurately by perspective viewing without surgery. Heretofore, this problem has not been solved. Also, with the growing use and acceptance of nuclear reactors, there is a need for the ability of scientists to view perspectively nuclear reactor fuel rods to inspect the rods for cracks, defects, etc. in order to prevent equipment malfunctions and to avoid harmful and dangerous accidents. No satisfactory solution to this problem has been determined before the invention described herein.
Also, in studying living systems biologists and physiologists need to observe within these systems the movement of various molecules such as nitrogen, oxygen, and organic molecules. These molecules can be "tagged" with atomic nuclei which emit annihilation radiation. A "camera" which would accurately image in three dimensions the locations of these radioactive molecules would be extremely useful in advancing knowledge about chemical processes in living systems.
In the prior art, it is known that some depth of a three dimensional source object emitting radiation can be perceived by viewing through a stereoscope two pictures of the source taken at different angles. See Tomographic Imaging in Nuclear Medicine, Chapter 17, published by the Society of Nuclear Medicine, 1972. This known method uses a parallel-hole collimator to filter out radiation which is not colinear with the holes in the collimator which would otherwise expose the radiation-detecting photographic film. Applicant's invention improves the reconstruction of the radiation source as seen by viewing multiple images stereoscopically by producing images from signals generated only by radiation which would pass through preselected regions in space. This apparatus and method of detection improves the quality of the three dimensional image as viewed through a stereoscope.
For other prior art of general interest, see U.S. Pat. No. 3,652,855 to McIntyre and Saylor (issued Mar. 28, 1972) for "Radiation Image Amplifier and Display Comprising a Fiber Optic Matrix for Detecting and Coding the Radiation Image Pattern" and Stereoscopy, pp. 285-289, by N. A. Valyus published by the Focal Press-London and New York.